You can explicitly specifiy a file using the path and filename tag; for example:
[usr/acufiles/file1.dat]
IDXFORMAT=17
[usr/rmfiles/file1.dat]
IDXFORMAT=21
sets
file1.dat in
usr/files/acufiles to IDXFORMAT 17 and
file1.dat in
usr/files/rmfiles to IDXFORMAT 21.
Note: To enable the use of filenames (without a pathname), set
BASENAME=ON in the [XFH-DEFAULT] section.